"Mean Girls" alum Lacey Chabert is mourning the death of one of her sisters.

In an emotional Instagram post on Tuesday, Chabert shared a graduation photo of her "beautiful" sister Wendy. In the caption, she wrote, "Our hearts are shattered into a million pieces that I don't know how we will ever put back together again now that you're gone."

"We love and adore you more than we can ever say and we will continue to forever and ever and ever," she continued. "The shocking loss has left us so broken hearted. Our lives will never be the same without my dear sister, but we cling to the promises of Jesus that we will be together again in eternity. Please keep our family, especially her two boys, in your hearts and prayers. Thank you so much."

Chabert shared no further details about Wendy's death.

The actress' message brought sympathy posts from Chabert's fellow Hallmark holiday movie mainstays, including "Full House" alum Candace Cameron Bure and "The Wonder Years" alum Danica McKellar.

"Oh my goodness, Lacey. I love you so much and am sending prayers and love to you," McKellar wrote. "I don't know what I could possibly do, but please call on me if I can do anything at all."

Bure wrote in part, "[W]e are praying for you, your family and Wendy's family. We love you, always here for you my sweet sweet friend."